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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

"The Royal Society now also agrees with the GWPF that the warming trend of the 1980s and 90s has come to a halt in the last 10 years."

And gleefully reporting that the Royal Society “admits that there are ‘uncertainties’” - I remember a Professor who drilled "numbers mean nothing without uncertainties!" into students, so this shouldn't surprise most people with scientific experience!

The Intergovernmental Panel on Climate Change (IPCC) carefully includes them with all its statements. The Society report is worth reading if you have time but if you want detail then read the IPCC report: the two agree on everything they both cover.

The Society split simple statements into 3 sections: widespread scientific agreement, widespread consensus but active discussion, and ‘not well understood’. Let's dig up a few gleaming nuggets of knowledge.

Comments

Are the GWPF reading the same Royal Society report that everyone else is ?
I understand that WUWT also like the report.

Are the so-called skeptics so desperate that they will avidly feed on any crumbs no matter how illogical to their own stance (see also the recent Loehle belief about the Ljungqvist paper) ?
Or do they really see reality in a different way, for some strange reason ?

If you mean Anthony Kelly and Alan Rudge as the two individuals they don't seem to be authors.

The authors are listed under

"Working Group
The Royal Society would like to acknowledge the members of the working group that produced this document"

While the two above are listed under

"Contributors
The Royal Society gratefully acknowledges the contribution of individuals who have commented on the document at earlier stages of its preparation. These individuals were not asked to endorse the document."

The article states:
"The decade 2000-2009 was, globally, around 0.15 °C warmer than the decade 1990-1999."
Make of that what you will.
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OK I will! That is a long way from the 6 ° C warming which some scientists have lead us to believe will occur in the next 100 years. Why should we believe the rate will accelerate?
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So far the warming has been far below the 6 ° C rate the scientists want to use for a doubling of CO2. Since we have had 1/3 of a doubling of CO2 we should have had more than 2 ° C warming we haven’t had this. [.7 ° C is the accepted value and less than ½ of that is from CO2 in the best case.] The relationship is logarithmic so this understates the expected warming.
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To get around this scientists have speculated that the ”missing heat” is stored in the oceans ! The problem is that since 2005 both the atmosphere and the ocean have been cooling.
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
http://www.woodfortrees.org/plot/uah/from:2005/to:2009/plot/uah/from:2005/to:2009/trend

Some have SPECULATED that the missing heat may be in the deep parts of the ocean but since they haven’t measured to test this speculation they don’t know. One article claims to have found 20 % of it.
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The most important and ignored part of the missing heat controversy is when the heat will return. ? The surface area of the ocean is orders of magnitude greater than the slight polar warming the article seem to find. When will the missing heat return to the surface where it can cause substantial warming ?
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Since we are only speculating where the heat has gone and have only speculation about how it got there how can we predict how long it will be until it returns ?
Answer: We can’t ! We have a theory of CAGW which DEPENDS upon the “missing heat ” returning in the next 100 years and we don’t know where the heat is and don’t know if or when it will return. Since we cannot find it we cannot measure it so we don’t know much of it exists.
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Despite all of this “the debate is over” and we should throw ten’s of trillions of dollars at the nearest politician to make it go away.

Sounds as though you have a hypothesis about a cooling ocean, NETDR, a hypothesis you prefer because (as your last sentence suggests) it fits your political perspective. You're touting a scientific case for what seems a political reason, only your case is incredibly thin compared to that offered by the IPCC. For my part, I'll go on listening to the scientists.

NETDR - your numbers are wrong. I refer you to Quantifying the human contribution to global warming, which shows that we expect to see ~1.4°C warming from the CO2 we've already emitted, but have only seen ~0.8°C due mainly to the thermal inertia of the oceans.

Rob Honeycutt - A study by James Hansen set 6°C as the *long-term* sensitivity to 2xCO2. This accounts for slow-acting feedbacks, as I discussed in a detailed look at climate sensitivity. However, the short-term climate sensitivity is in the 2-4.5°C range, most likely around 3°C. Thus NETDR's reference to the 6°C long-term senstivity is inappropriate and incorrect.

The point is that what you see is what you get. We have seen approximately the mount of warming expected without feedback. [Or less ] That isn't scary enough !

As far as the thermal inertia of the oceans that has been debunked by the "missing heat" arguments refereed to above. If it is hiding at the bottom of the oceans why do we care? When will it return is more germane ?

The "long term" feedbacks Hansen refers to have the same problem. Where is the heat now? When will it return ?

Ok if you want to say 3 ° C so be it but when the scientists want to scare the public they use the higher number.

The RS document seems to have a substantially less forceful tone than its predecessors, which took a very polemic stance of debunking 'dangerous myths.'

Much more prominence is given to uncertainties.

For example, they state:

“It is not possible to determine exactly how much the Earth will warm or exactly how the climate will change in the future.

“There remains the possibility that hitherto unknown aspects of the climate and climate change could emerge and lead to significant modifications in our understanding.”

Now if I posted a comment on those lines, I suspect many on this site might take issue with me given my role as one of a number or 'sceptics in residence.'

I suspect the AGW debate follows the time-worn Hegelian path of thesis, antithesis, & synthesis. So-called sceptics increasingly acknowledge the basic physics and strive to educate their readership on the blogosphere. Warmists increasingly reach out to sceptics (and sometimes get tarred and feathered for their troubles).

Nevertheless, we do not yet have synthesis or complete 'consensus.' Nor should we. The science is never settled. In the late 19th century, many believed that physics under the Newtonian paradigm had answered all the basic questions. That all changed in the early 20th century (no doubt, as a non-physicist, I may be grossly over-simplifying the history of relativity and quantum mechanics). Settled science however becomes a stagnant backwater.

Then I saw Joe Romm having a cow over it on his blog, so I thought again.

But I think Joe is wrong on this one. The public are not clued into the nuances of denialism and will see it as an endorsement of the science of global warming. There is enough in the document to convince readers of the reality of global warming.

#2 HR: I've edited the first section. One of them is listed under the working group that produced the article (what I would call a co-author) and one of them as a contributor. I've changed the wording and now I hope it combines accuracy with succinctness.

chriscanaris,
what the guide says and you report here sound a little obvious.
What I found in the new version of the guide is that they utterly fail to give useful information to the public. If this is the contribution of the skeptics i'd be happy to live without it.

“There remains the possibility that hitherto unknown aspects of the climate and climate change could emerge and lead to significant modifications in our understanding.”

Of course, and that is a classic crumb which has been thrown to the so-called skeptics, and perhaps why some of them are more keen on the Royal Society than previously, i.e. whereas previously the RS was part of the great big conspiracy, now they have apparently turned about-face and embraced denialism (according to the GWPF, anyway). Supposedly this no doubt means that scientists are slowly moving away from the lies they have previously been telling about AGW, because they aren't interested in the money and power anymore, but have developed a conscience thanks to great men like McIntyre, Watts, etc.

Anyway, after that fantasy, here's another possible future :

"There remains the possibility that hitherto unknown aspects of gravity and the theories of relativity and quantum physics could emerge and lead to significant modifications in our understanding."

NETDR, you are rejecting physics in your comments. There is still a net planetary energy imbalance (measured by satellites), so we know that there is more 'warming in the pipeline'.

Climate scientists almost never refer to 2xCO2 climate sensitivity as higher than 3°C, so I have no idea what you're talking about. Perhaps you're referring to the warming projected by 2100, which may be as high as 7°C because atmospheric CO2 may rise well above 560 ppmv.

#3 NETDR: I suggest reading a few of the articles on this site or elsewhere that try to explain the concepts of radiative forcing, climate sensitivity and what this means for future temperature change.

Climate sensitivity is a very technical term and in most cases we have reported equilibrium climate sensitivity - which can take a significant time to occur! We also have transient climate sensitivity, which is a bit more relevant and is less than the equilibrium value.

Equilibrium says that if you double CO2, you'll eventually get 2-4.5 C warming, most likely 3 C. Your 6 C value comes from almost doubling CO2 twice by 2100, which we haven't done yet! Heating will probably accelerate from today's value.

We have increased CO2 by 40%: aerosols approximately cancel out the other greenhouse gases but there are big uncertainties in the cloud effects so they might not be, or they might be partly cancelling out CO2.

We expect about 1.4 C warming from CO2 eventually, but it takes time for this to happen. We have climate models that tell us how long we expect to wait, and current temperature change is well within the uncertainty bounds of current generation models - we are warming and the rate we're warming at does not contradict eventual 6 C warming if we double CO2 twice.

NETDR... "Ok if you want to say 3 ° C so be it but when the scientists want to scare the public they use the higher number."

No. I think you're hearing what you want to hear. Problem is you have to listen very closely to what scientists say because there is usually a lot of information imbedded in what and how they say things. Scientists are generally extremely careful to be accurate about what they say (i.e., Phil Jones' "no statistically significant warming").

What you are doing is EXACTLY what you are accusing scientists of doing, only in reverse. You are claiming 6C of warming isn't being seen in current trends, when no one even suggests that you would see them now.

#9 NETDR: "Ok if you want to say 3 ° C so be it but when the scientists want to scare the public they use the higher number."

This is a confusion between climate sensitivity and what is projected to happen.

Let's say the shopkeeper tells you that an apple costs 3p, but if you buy 2 apples it will cost you 6p. Both of these are true, but the 2 numbers are different and 6p looks worse than 3p.

The 3C figure is commonly quoted as the eventual warming if you double CO2 once. 6C is what we expect if we double CO2 twice, which is what is expected to happen under 'business as usual'.

It gets even more complicated as 6C is the upper bound of warming by 2100 which includes us heading for 2 doublings of CO2 and the upper bound in the uncertainty of climate sensitivity (3 C is the best estimate, but models still calculate a good chance of up to 4.5 C)

The spin the GWPF is putting on the Royal Society guide is simply outrageous. It is worth noting that the GWPF has charitable status in the UK and as a result enjoys certain tax breaks and financial benefits. The GWPF stated 'charitable' objectives are:

"TO ADVANCE THE PUBLIC UNDERSTANDING OF GLOBAL WARMING AND OF ITS POSSIBLE CONSEQUENCES, AND ALSO OF THE MEASURES TAKEN OR PROPOSED TO BE TAKEN IN RESPONSE TO IT, INCLUDING BY MEANS OF THE DISSEMINATION OF THE RESULTS OF THE STUDY OF, AND RESEARCH INTO

A THE SCIENCES RELEVANT TO GLOBAL WARMING
B ITS IMPACT UPON THE ENVIRONMENT, ECONOMIES AND SOCIETY
C AND THE ABOVE-MENTIONED MEASURES"

It seems to me they are actually doing the complete opposite of the above and are actively misleading the public. For some time I've wondered if there is a basis for complaining to the Charity Commission (the body that regulates charities in the UK) about the GWPF. Their status as an educational charity is dubious to say the very least.

The thirty year trends from MSU, SST, and Land/Ocean indices are all at or below 1.7° C per century.

Given that most of the IPCC scenarios indicate a deceleration of temperature trend, there's some 'splain'n to do. as to why the observations are not only below the mid range (3° C) but even below the best estimate for the low end scenario (1.8° C).

Hegel was talking about philosophical ideas, not scientific ones. Besides Hegel was a lousy scientist - in his youth he published a book stating on philosophical grounds that there could not be more than seven planets.

Scientific ideas usually survive on an "all or nothing" basis. There was no synthesis between Newton's and Einstein's theories.

I suspect, though, you may be partially right. The denialists are pivoting from science (where they are losing badly) to politics, where they may even be winning. Look at the way the Tea Party has embraced denialism. "Alarmism", "radicalism" and "bringing politics into science" are becoming the main accusations.

The Tea Party in power will either have to betray their constituents (which is possibly) or work out some sort of modus vivendi with science. A scientists vs politicians clash is possible, which will make the "science wars" of George Bush's terms look like a kiddies party. Some Tea Partiers are already threatening Congressional Investigations into climate science.

So, if there is going to be a synthesis, it will have to be on the politics front. And the best hope is that Tes Partiers do not follow their rhetoric but are more reasonable than they seem. The other hope is that they lose. Given the demeanour of political denialism and the state of play in US politics, I am not optimistic.

I know the above seems overly focused on American politics, but that is where the frontline is at, right now.

"Climate scientists almost never refer to 2xCO2 climate sensitivity as higher than 3°C"

Unless those climate scientist happen to be part of the IPCC, in which case they do.

"likely to be in the range 2 to 4.5°C"
"Values substantially higher than 4.5°C cannot be excluded"

http://en.wikipedia.org/wiki/Climate_sensitivity

Of course there is 'uncertainty' because there is uncertainty in the IPCC range and the observations are all below the low end of that range.

00

Moderator Response: Unless you'd prefer your comments on this thread regarding specific features of climate science be deleted, you'll want to take each specific scientific problem you feel exists to the appropriate thread, as has already been suggested.

ClimateWatcher, you would be more credible if you gave the whole quote, thus :

Progress since the TAR enables an assessment that climate sensitivity is likely to be in the range of 2 to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C. Values substantially higher than 4.5°C cannot be excluded, but agreement of models with observations is not as good for those values.

Which is not based on "those climate scientist [who] happen to be part of the IPCC", but a vast body of work given here :

Lest anybody be confused by NETDR's rarefied treatment of ocean heat, here's a synopsis of the latest thinking on OHC measurements, "Robust warming of the global upper ocean" where the matter can further be discussed.
************
Lest anyone be confused by Doug’s study of ocean heat.

The XBT which this study is based upon only goes 460 Meters deep[for most measurements] while the more accurate Argo buoys go 2 kilometers deep. The XBT’s are launched from ships and so are weighted toward warmer shipping lanes.

There are 3000 Argo buoys which sample the whole ocean except under the ice packs.

Which s more accurate ?

The Argo buoys have found cooling since 2005.
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/

There were several people who objected to my using 6 ° C for a doubling of CO2 which was taken from Dr Hansen 2008. He had a short term value of 3 ° C also if that is more pleasing. We aren’t warming nearly that fast either.

The earth s a long way from being on track for even 3 ° C of warming in 100 years.

The article
The decade 2000-2009 was, globally, around 0.15 °C warmer than the decade 1990-1999."

This projected warming would be 1.5 °C in 100 years which is not enough to spend tens of trillions of dollars to avoid.

Don’t get me started on models. I coded them professionally and am less than impressed with “hindcasting”. It is a good start but only a start.. They have to insert a huge plug to insert natural cooling to account of the warming which isn’t happening according to prediction

As a general note to anybody making comments here on Skeptical Science, if you find yourself writing an extended comment on a specific avenue of inquiry, be sure it's posted in a place conducive to coherent, nonduplicative discussion of the particular research topic you have in mind.

Not to pick on NETBR in particular, but the above comment is an excellent example of producing an intractable salad of issues, each of which are deserving of separate discussion.

As always, the "Search..." box at upper left is your friend when it comes to locating opportunities to continue conversations as well as avoid rehashing issues in a myriad of different locations.

Folks, NETDR is a troll. It's obvious from the way he misrepresents facts and fails to stay on-topic, presenting a mish-mash of half-baked arguments that fall apart under the shallowest of scrutinies.

His goal is to waste our time by restating the same arguments over and over again, hoping to create enough chaos on these threads to prevent any reasonable scientific discussion.

There's only one way to deal with trolls: ignore them. Don't respond to their trolling, and they'll go away. Anyway, people genuinely seeking serious scientific information will be turned off by his political references, and there are moderators who can prevent him from going too much off-topic.

archiesteel at 07:45 AM, whilst your warnings are obviously directed at those with limited capacity to assess such matters themselves, the object of sites such as this is to allow readers on both sides to both present and accumulate knowledge on the subjects being debated, and as such should be left to the participants and ultimately the moderators to decide on the relative value of any contribution without having to be told what value any may or may not be contributing.

@johnd: I can't count the number of onlin forums (which includes comment sections) I've participated in since I started back in the day of BBSes. This long experience has given me the ability to spot a troll a mile away.

Now, you may want to engage this individual yourself and try to have a coherent discussion, but my *humble* suggestion to those who'd be tempted to keep re-explaining the same things to him (even though he's clearly not interested in "accumulating knowledge") is to just ignore him, or kindly point him to the appropriate argument in the list, but not waste time writing long rebuttals he's not even going to read. That's all.

BTW, I haven't heard any of the serious AGW critics here denounce the weak scientific arguments repeatedly pushed by such commenters as NETDR, thingadonta and cruzn246. You have to realize that, ultimately, such crude attacks on the science hurt your side of the debate more than mine...

If this is a site dedicated to teaching neophyte true believers their beliefs I will leave you to your beliefs. If it is a site willing to debate the opinions of others I an willing to oblige.

I think that much is to be gained by sharing points of view and arguments between skeptics like myself and true believers [or whatever you call yourself] such as yourself. I am tired of posting on skeptical sites because it is like preaching to the choir.
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Don’t expect me to bow before your particular study there may be serious problems with it and I will point them out if I am able. You are free to do the same.
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I have read many articles on this site and found gaping holes in many of them. Possibly they were just too basic and omitted knowledge I already had !

I expect you to object and bring forth your best arguments. I follow up and read many of the links you post but I have read many of them before. I have read several books and several hundreds of articles most of them explaining the non skeptical arguments. I probably know them as well as most of you so it is patronizing to tell me to read argument XYZ as if it were a refutation of my point. Make the argument if you are able.
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Name calling and saying that my arguments have been debunked while satisfying to you is pointless and untrue.
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The missing heat is still missing and despite the XBT study trying to find it still lost.
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Without it the 3 ° C warming for a 2XCO2 is a fairy tale. So far it isn’t happening as your own article admits. There is no reason to believe warming will suddenly accelerate. Until the missing heat returns it won’t.

So go back to reinforcing each others misconceptions and ignore me if you prefer.

I invite you to post your arguments on wattsupwiththat.com if you feel capable and don’t mind getting roughed up.

If there are unwritten policies like “one argument per post” let me know I will comply.

"If this is a site dedicated to teaching neophyte true believers their beliefs I will leave you to your beliefs. If it is a site willing to debate the opinions of others I an willing to oblige."

It's neither, actually. It's a site to debate science. Not opinion. Not politics. Science.

Just the type of language you use ("true believers," etc.) shows you're not really interested in learning the science, but only in picking up fights because, well, you decided you didn't believe in AGW and nothing will make you change your mind.

"I think that much is to be gained by sharing points of view and arguments between skeptics like myself"

This is not a debating society. Nobody ever refers to argument XYZ. We all read or refer to papers, reports, statistics, articles, graphs. There may be an argument about which is more relevant or useful, but it's never an argument in the way you're describing.

Back to "Uncertain times.." I know that there is no change in the RS's position about the science.

However I do think the restatements and the emphasis on uncertainties is a classic example of the Freudenberg & Muselli "Asymmetry of Scientific Challenge" problem. There is no change in the science nor in the RS view of the science, but the RS's most recent document differs significantly =in tone= from the 2007 public statement.

No matter how much anyone repeats the mantra about there being no change in the science or the stance. For the people who poked and prodded the RS into producing this, it is a vindication of their approach.

I would have been a lot happier if the RS had said they have examined the scientific papers published since 2007 and statistics since then. These indicate that the earlier statement should now be stronger in these ....... various/particular/different ways.

I don't want to go too far off topic but the thesis, antithesis, synthesis meme applies across a range of fields and especially in politics and policy which is where the AGW debate must play itself out.

In science, we see it in terms of competing paradigms jostling for their place in the sun.

Saying Hegel was a lousy scientist because he published a tract stating that there could not be more than seven planets on philosophic grounds is to apply to him the standards of a different era.

Newton was said to dabble in alchemy and astrology (the latter is a matter of some dispute) yet none would deny him his greatness. Moreover, Einstein's physics are perfectly compatible with those of Newton. When dealing with velocities on a human scale, the distortions of time and space emanating from relativity become so negligible that Newtonian physics apply.
Coming back on topic, I note that this has yet to happen in climate science not because of a dispute about the laws of physics but because of the complexities of the systems involved create uncertainties about the weighting to give to a plethora of feedbacks.

This creates a tension between those who desire urgent action and those who see the uncertainties. The former fear that the latter undermine their cause. The latter include those who may honestly feel that the uncertainties are too great to warrant drastic steps and at the more extreme end some who would go so far as to accuse scientists of being prepared to lie or stretch the truth to advance their agenda. The issues are well captured by the controversy between Stephen Schneider and Julian Simon. For what little it’s worth, I am much more sympathetic to Stephen Schneider's take on the dilemma even though philosophically I would be closer to Julian Simon.

NETDR:
"If this is a site dedicated to teaching neophyte true believers their beliefs I will leave you to your beliefs. If it is a site willing to debate the opinions of others I an willing to oblige."

Surely science isn't about peoples opinions, if that were true then it people would be discussing whether humans landed on the moon or if UFOs exist.
Anyone can have an opinion, the fact they do doesn't make it true.

Given the general level of treatment of this RS report, it seems geared to a lay audience. In light of that, what surprises me is how it commits an all-too-common error of omission by repeatedly referring to "uncertainty" without carefully explaining the meaning of the term when it is employed in scientific communications.

This a pretty astounding oversight given that confusion over the meaning of the term "uncertainty" is a hurdle for the public when it comes to understanding science. Uncertainty is a didactic challenge we've known of for decades, has a particularly high profile when it comes to discussing climate change and in fact has been manipulated and exploited for rhetorical purposes by various entities interested in policy outcomes related to climate change.

Disagreement over communicating uncertainty was the impetus for an update to the RS report yet the report entirely fails to address uncertainty as a key topic.

Motivation for a redo hinged essentially on a perceived process problem with the first report, namely that the first report conveyed an exaggerated sense of risk. Beyond causative mechanisms, risk is about probability. Our ability to judge the probability of risk from climate change is rooted in the uncertainty of scientific findings having to do with climate change. Conveying a useful understanding of the risk we're exposed to by climate change thus absolutely requires a proper explanation of what uncertainty means in the scientific sense. By failing to accomplish this first and arguably most important task, the RS report fails to improve on the first attempt.

Regardless of one's stance on climate change, as a communications tool this report is a failure right out of the gate when it comes to helping readers from the general public understand the significance of the scientific findings it covers.

The Ville at 17:55 PM, if all the contributors to this site were climate scientists, then perhaps the discussion here would be more about the science behind the research they are presenting and less about opinions.

However almost exclusively all the work being referred to here by the contributors is the work of others, and the reason it is presented to support a particular argument is because, in the contributors OPINION, it is relevant and carries some authority for a number of various reasons.

Often it is because they are of the opinion that the author of the study has credibility, and so all work he produces carries the same credibility even though the detailed science is beyond those who present it here, but that may not be the opinion of everyone.

At other times the work may be, in their opinion, relevant to the argument, but again as we often see here, in the opinion of others, it is at times rejected as being of little relevance.

At other times when the research is unable to determine with any certainty whether the nett result points to one outcome or another opposing outcome, and different scientists are able to make cases for both scenarios, the case selected by a contributor here will be based on their own opinion as to which scenario seems most likely or is most consistent with their own position, and so on.

So whilst you may consider that science is not about opinions, how different contributors select and present supporting arguments on this site is most definitely all about opinions.

The reason for the existence of this site is primarily economic, JohnD, and that is why discussions here have a tendency to swerve away from science and into unfounded personal opinions, such as that thousands of petawatt-hours per year of additional energy retained on the planet will somehow result in no disruption to the accustomed behavior of our climate (your opinion, based on your many comments here).

Ask yourself, where is the website frequented by members of the lay public where models of Earth mantle convection are hotly debated?

The "energy flux" powering this site and the myriad other locations where discussions of climate science involve the general public is the future course of several trillion dollars per year, now concentrated in the hands of fossil fuel concerns but possibly to be redirected to other means of energy manipulation.

That same energy is what has driven the Royal Society to revisit their statement on climate change.

NETDR:
"Ok if you want to say 3 ° C so be it but when the scientists want to scare the public they use the higher number."

Who is 'the scientists'?
But in any case, the higher number is possible.
It's like any engineering project, a component will have a range of tolerances within which it will work. The upper tolerance may result in a failure, but only 1 in say 10,000 components may be in the upper tolerence.
So you can expect 1 in 10,000 products to fail due to that component.
eg. the low probability of failure due to some components being in that upper tolerance band, doesn't stop some failures happening.

In the case of climate temperature tolerances, we have the one range. If we use the climate 'component' we don't know if it is in the low or high range of temperature. Hence the issue isn't that 6c won't happen, it is the case that we are uncertain, but it could.

Given that it could, however unlikely, we have to assess just what the damage would be for that scenario and weigh that up against it being less probable.
Given it is likely to be seriously worse, that has to bring it into the more probable tolerance band as a risk to be considered.

So is it 'alarmist' to consider the higher temperature ranges?

No, because if we applied the same logic to say a nuclear power station, we would remove a lot of the safety mechanisms because the probability of a serious accident happening would be even smaller than a 6c temp rise.

You are NETDR fooling yourself if you believe uncertainties are a reason to pull back. Such thinking does not occur in modern engineering and if it does you get oil spills in the Gulf of Mexico and other similar accidents.

The Ville 46
Wrote
You are NETDR fooling yourself if you believe uncertainties are a reason to pull back. Such thinking does not occur in modern engineering and if it does you get oil spills in the Gulf of Mexico and other similar accidents.

*******
Here we have the famous precautionary principal which is primarily used to justify massive expense that the science is too weak to support.

The earth will be hit by a comet or asteroid large enough to destroy civilization. The question is not if but when. We should be practicing moving rocks in space right now to avoid this, in my opinion, far more likely catastrophe.

The damage done to society in the form of diverted resources is far less and the benefit is greater, so where are the space ships? CAGW will have to get in line with all of mankind’s other problems.

If we divert the tens of trillions of dollars from mankind’s real problems for an unlikely alternative you get starvation and even death for some.

Since the subject of this article is "uncertainties" how to deal with them is in my opinion on topic.

@johnd: "So whilst you may consider that science is not about opinions, how different contributors select and present supporting arguments on this site is most definitely all about opinions."

You're stretching the meaning of "opinion," here. There's a difference between citing scientific work because you have the opinion that it addresses a certain point, and basically stating your opinion that (for example) CO2 is not a greenhouse gas without providing actual evidence to support that opinion.

For example, you objected to my earlier post where I gave my opinion that NETDR is a troll. That is an example of an opinion that, according to you, has no place on Skeptical Science, and to a degree I do agree with that evaluation - I wish I didn't have to make those kind of posts, but when trolls start to take over comment sections you have to act.

I'm curious, though: can you explain how NETDR has helped move the scientific discussion forward? Do you agree with the arguments he's posted? If not, why didn't you say so? Could it be because of the unspoken rule among contrarians that you never argue with someone on "your side," even if they say thing that are clearly false?

I would expect serious skeptics like you, BP and others to be the first to correct erroneous claims from posters like NETDR - after all, their unsupported attacks reflect badly on *all* skeptics.